Search results for "Behavior"
showing 10 items of 13975 documents
The Usefulness of Biometrics for the Study of Avian Connectivity within Europe. A Case Study with BlackcapsSylvia atricapillain Spain
2012
Summary. The use of biometrics in studies of migratory connectivity is still relatively infrequent in Europe. This is partly due to the fact that biometrics is a less accurate tool when compared to ringing recovery data, or such techniques as stable isotope analyses, use of geolocators or satellite telemetry. Combination with one of these (recovery data) allows us to test the usefulness of biometrics in connectivity analyses, as well as to evaluate/quantify the influence of migratory behaviour on phenotypic traits such as flight morphology. We used historical recovery data, together with flight morphology data obtained from a consistent collection protocol during a three-year ringing progra…
Analysis of gene flow and habitat patch network for Chazara briseis (Lepidoptera: Satyridae) in an agricultural landscape
1997
Abstract A fine geographic-scale population genetic structure analysis was performed for the endangered butterfly species Chazara briseis in the region of Halle an der Saale, Germany, for the investigation of gene flow and possible effects of habitat fragmentation on genetic variability. Patterns of genetic variance were estimated by allozyme electrophoresis and quantified with F -statistics. Levels of genetic variation were high, expected heterozygosity H e = 0.20, and mean number of alleles per locus, A = 1.93, indicating large population sizes. Butterflies inhabiting the study area probably constituted just one population and the fragmented nature of the habitat patches did not substanti…
Effects of fragmented breeding habitat and resource distribution on behavior and survival of the bank vole ( Myodes glareolus )
2010
Habitat fragmentation causes negative population trends or even local extinction in many species. Understanding the role of fragmentation on behavior and space use of animals is an essential part of revealing the mechanism behind observed population declines. We studied experimentally the effects of small-scale habitat fragmentation on the distribution and movement of bank voles (Myodes glareolus) in seminatural enclosures. We predicted that besides habitat structure, availability of two resources, food for both sexes, and receptive females for males, determine individual distribution. We manipulated female density (either 0, 4, or 12 per enclosure) and followed movements of radio-collared …
Changing female spacing behaviour and demography in an enclosed breeding population of Clethrionomys glareolus
1988
The social organization of Clethrionomys glareolus Schreber was studied by live trapping in an enclosure of 0.8 ha in Central Finland between the years 1982–1986. The enclosure consisted of three habitats: abandoned field, brushwood, and moist spruce heath forest. The population density increased from 50 voles ha−1 in 1982 and 1983 to 150 ha−1 in 1984 and 1985. In the summer of 1986 the population crashed to almost zero. In the summer of 1984 after winter breeding the number of breeding females grew to 22 compared with 6–7 in previous years. In 1984 the mature females changed from territorial to group behaviour. During the high population density in 1984 and 1985 breeding stopped already in…
Galerucella nymphaeae (Col., Chrysomelidae) grazing increases Nuphar leaf production and affects carbon and nitrogen dynamics in ponds.
1990
The grazing effects of the waterlily beetle Galerucella nymphaeae on Nuphar lutea stands were studied in three ponds in Central Finland. Production of floating leaves of N. lutea and growth in the G. nymphaeae population were investigated in the ponds and bioenergetics of the beetle larvae in the laboratory. Combination of field and laboratory data enabled estimation of the effect of the beetle on the production of floating leaves of N. lutea and the consequences of grazing for the input of detritus from Nuphar into the ponds. Adults and larvae of G. nymphaeae consumed 3.0–6.1% of the net annual floating leaf production during the growing period. In addition to consumption losses, feeding a…
Hieracium barrelieri, a new hawkweed species from S Italy, with notes on Tenore’s Hieracium murorum var. barrelieri (Asteraceae)
2015
A new species from Montevergine in Campania, Hieracium barrelieri, is described in detail. It is closest to H. acanthodontoides of H. sect. Acanthodontoidea. H. murorum var. barrelieri, an obsolete taxon described by Tenore, is also discussed, as it was partly based on the same population.
Coauthorship networks and institutional collaboration patterns in reproductive biology.
2007
Objective Reproductive biology is a highly productive area. By analyzing papers published in the major journals in the period 2003–2005, the collaborative patterns were characterized. Design Original research papers published in 2004 in the journals included in the first quartile of the category "Reproductive Biology" of the Journal Citation Reports (2005) were selected. A bibliometric analysis was carried out with the information obtained, thus building up the networks of coauthorship and institutional collaboration. Result(s) A total of 4,702 papers were analyzed, 96.75% signed in collaboration by two or more authors, the authors per paper index being 5.24; 73.73% of the papers were colla…
Aetiology for the covariation between combined type ADHD and reading difficulties in a family study: the role of IQ
2012
Background: Twin studies using both clinical and population-based samples suggest that the frequent co-occurrence of attention deficit hyperactivity disorder (ADHD) and reading ability/disability (RD) is largely driven by shared genetic influences. While both disorders are associated with lower IQ, recent twin data suggest that the shared genetic variability between reading difficulties and ADHD inattention symptoms is largely independent from genetic influences contributing to general cognitive ability. The current study aimed to extend the previous findings that were based on rating scale measures in a population sample by examining the generalisability of the findings to a clinical popul…
Larval Arrest in Development of Tribolium castaneum (Coleoptera: Tenebrionidae)
1986
Arrested larval development (in the last larval instar) of part of the total larval population has been detected in moderately crowded situations (40 larvae in 2 g food) in Tribolium castaneum (Herbst) cultures This phenomenon is the same found previously in highly crowded cultures of Drosophila melanogaster (Meigen) and other related species. The arrest may be viewed as a mechanism of physiological adaptation of organisms to competitive situations.
Determinants of jaguar occupancy at the northern range edge
2020
Identifying factors promoting jaguar (Panthera onca) occupancy is crucial for planning effective conservation and management actions that can contribute to long-term population viability. We used camera-trapping and modeled factors affecting detection and occupancy for jaguars in Sonora at 149 sites during August-November 2008 and 2009. We measured 24 covariates presumed to affect detection (n = 6) and occupancy (n = 18) at camera sites, including sampling period and various habitat characteristics. We obtained 29 jaguar detections at 19 sites (naive occupancy = 0.12) in 5455 trap-days of effort. Jaguar detectability (p = 0.16 +/- 0.05) was negatively affected by human presence and varied b…